There is no rule book for telling someone a son, a daughter, a husband or wife has died in war. At least that's what you'd think.

Turns out there is a protocol, one that Capt. Tony Stone (Woody Harrelson) follows rigidly in Oren Moverman's "The Messenger." That protocol dictates that soldiers deliver the message of death only - no embraces, no consoling. Just deliver the message and be gone.

Staff Sgt. Will Montgomery (Ben Foster), wounded while serving with heroism in Iraq and new to the Army's Casualty Notification service, his own horrific memories still as fresh as the scars on his body, is less by-the-book. He even goes so far as to embark on a tentative relationship with a widow (Samantha Morton) whose home he has visited with news of her husband's death - an extreme breach of protocol that rankles Stone to no end.

But that relationship, between Montgomery and Olivia (Morton), is secondary in the film. Indeed, it's given short shrift in Moverman's otherwise excellent movie. The real bond is the one that develops between Stone and Montgomery. They share little in common but duty. But that duty is so incredibly intense that it trumps most of their differences.

Survivors react differently to the message Stone and Montgomery deliver. There is grief, of course, but also disbelief, denial, appreciation, anger, even violence. For Stone and Montgomery, there are dread and, most profoundly, guilt.

Stone saw action during the first Gulf War. A recovering alcoholic, he's cagey about his experiences. Montgomery is simply mute about his; he tries to come to terms with what's haunting him by way of beer and booze-fueled physical explosions of anger while alone in his Spartan apartment. But he doesn't talk about what he saw and did, because he simply can't.

At least not yet. If truth is the first casualty of war, trust must rank highly, as well. Montgomery's girlfriend, Kelly (Jena Malone) may meet him for a tryst, but she got engaged to another man while he was in Iraq. Montgomery is also wary of Stone, though a series of bonding experiences will serve to bring them closer until Montgomery can finally unburden himself to him.

In one scene, Montgomery and Stone show up unannounced (though not entirely uninvited) to Kelly's wedding reception. They're drunk (Stone's sobriety is a moving target at this point), rude and more than a little obnoxious. And yet no one, least of all Kelly, knows quite what to do with them. Kelly's husband offers an uncomfortable little toast about heroism, but that's not what Montgomery is after. He is still an open wound, yet his job is to spread a message of grief and loss. What does that do to a man? How can he not crave some sort of companionship, some sort of guard against those lonely nights in his apartment?

Foster is outstanding, giving a beautifully intense and moving performance. We see more of him than Stone sees, certainly more than Olivia does, but we still can't get at what's going on in his head. Foster depicts rage, frustration, confusion and loss in a quietly brilliant piece of acting.

Harrelson is quite good, as well, his quirks as an actor serving him, and the film, well; here, there's a reason for them.

"The Messenger" delivers what it has to say without sensationalism or political posturing. That restraint, along with the quality of the performances, makes it all the more powerful.